Reconstructive surgery often involves drilling into bone to attach soft tissue such as ligament and tendon grafts, as well as various artificial replacements and/or attachments, for articulated joints. In particular, reconstructive surgery involving the anterior cruciate ligament (ACL) of the knee is becoming particularly significant because the effectiveness of reconstruction can have a profound effect on the subsequent mobility of the patient. Similarly, an improperly treated ACL injury can be a permanent detriment.
A damaged ACL is often replaced with a graft from a patellar tendon or a semitendinosus tendon. Such a repair is facilitated by tunnels formed in the tibia and/or femur for use in implanting the graft in the patient's knee. The graft may then be secured in the tunnels by fixation means, such as interference screws or sutures tied to screw posts. The femur, in particular, because it often bears the entire weight of the patient, and being the largest human bone, may be relied upon to accommodate a substantial connective force from a surgically added structure. Attachment of grafts, therefore, is often performed at a structurally sound location on the femur.
Typically, when performing an outside-in drilling procedure, a drill guide adapted for insertion into the knee joint locates a drilling exit point on the femur, while a surgeon manipulates the handle of the drill guide to locate an entry location. However, conventional drill guides for directing placement of the drilled hole are universal, using a single design having a fixed relationship between an aimer arm and a handle to identify a point of drilling. Conventional approaches, therefore, do not distinguish a left from right knee, nor individual differences in the bone configuration of an individual patient, which compromises the ability to locate an optimal entry point for drilling. Surgeons may attempt a similar range of application by employing fixed left and right guides, or a series of fixed angle guides for both right and left application. However, this results in a trial and error administration as well as requiring the manufacturing of a range of multiple fixed angle guides.